Growth portfolio finally takes the lead
- Biogen is moving away from a shrinking MS base and toward Alzheimer's, rare disease, immunology, and eye disease products.
- In Q2 2026, the growth portfolio generated over $1 billion and officially outpaced legacy MS revenues.
- The Apellis deal closed in May 2026, contributing $128 million in partial-quarter revenue from SYFOVRE and EMPAVELI.
- LEQEMBI IQLIK secured approval for both starting and maintenance home doses, removing a major infusion bottleneck.
- The bear case centers on old MS drugs fading faster than expected and the debt burden from the Apellis deal.
A turnaround with proof, not just promises
Biogen used to be mostly an MS drug company. That old base is still large, but it is shrinking as TECFIDERA faces generics and TYSABRI faces biosimilar competition. The key change is that the newer products are now big enough to matter. In Q2 2026, the growth portfolio crossed $1 billion, solidly beating the remaining legacy MS products.
The bull case got stronger after Biogen closed the Apellis acquisition in May 2026. The deal adds SYFOVRE for geographic atrophy, an eye disease that can lead to vision loss, and EMPAVELI for rare immune diseases. The partial quarter alone brought in $128 million. It gives Biogen more near-term sales, rather than asking investors to wait years for pipeline trials.
LEQEMBI also moved forward. The FDA approved LEQEMBI IQLIK for at-home starting and maintenance doses. That matters because the older IV version needs infusion center time, which can slow patient starts. Easier use does not guarantee fast adoption, but it attacks one of the biggest barriers.
The bear case is still real. Biogen paid about $5.6 billion for Apellis, adding debt and near-term earnings dilution. SYFOVRE competes in a market where promotion and doctor confidence matter. Biogen paused its own MS BTK inhibitor because the market is too crowded. The company now has a better growth path, but it still has to prove that the new portfolio can outrun the old decline.
Replacing MS cash with new launches
Biogen makes money by selling prescription drugs, earning collaboration revenue, and collecting royalties. The old engine is MS. TYSABRI, TECFIDERA, AVONEX, and PLEGRIDY still bring in large sales, but most of that group is under pressure from generic competition. VUMERITY is the exception inside the oral MS group.
The new model is launch-heavy. Biogen is pushing LEQEMBI, SKYCLARYS, ZURZUVAE, QALSODY, high-dose SPINRAZA, and now Apellis medicines. This takes sales spending, doctor education, patient support, and payer coverage. Biogen is using its cost cuts to help fund that shift.
Where it breaks is simple. If LEQEMBI starts stay slow, SYFOVRE loses share, or SPINRAZA keeps losing patients to oral and gene therapies, the company could be stuck between a fading legacy business and an expensive growth plan.
The drugs that decide the story
Legacy MS franchise
TECFIDERA, TYSABRI, AVONEX, and PLEGRIDY still matter, but the group is under pressure from generics, biosimilars, and patient shifts to newer options.
VUMERITY
Biogen now counts VUMERITY as a growth product. It generated $197 million in Q2 2026, making it the bright spot inside MS.
LEQEMBI
LEQEMBI is Biogen's Alzheimer's partnership with Eisai. The approval of LEQEMBI IQLIK for at-home doses could make treatment easier for doctors and patients.
SPINRAZA
SPINRAZA treats spinal muscular atrophy. The high-dose regimen was approved in the U.S., E.U., and Japan, which helps Biogen defend the franchise against oral and gene therapy rivals.
SKYCLARYS, QALSODY, and ZURZUVAE
These newer launches cover Friedreich's ataxia, SOD1-ALS, and postpartum depression. In Q2 2026, SKYCLARYS generated $168 million and ZURZUVAE reached $71 million.
SYFOVRE and EMPAVELI
Biogen gained these drugs through Apellis. SYFOVRE gives it a large eye disease market, while EMPAVELI adds rare immune disease revenue.
Late-stage pipeline
Key pipeline bets include BIIB080 for Alzheimer's tau biology, litifilimab for lupus, and felzartamab for kidney and transplant-related immune disease.
Revenue mix transition
The mix uses Biogen's Q1 2026 revenue disclosure. Product revenue includes MS, rare disease, biosimilars, and other medicines. The Apellis products will change this mix in future filings.
What could still go wrong
Apellis integration and SYFOVRE pressure
High impact · Medium oddsBiogen paid about $5.6 billion for Apellis, which adds near-term earnings dilution and debt. SYFOVRE sells into geographic atrophy, a market where rivals, doctor confidence, and sales effort can shift share. If Biogen cannot stabilize or grow SYFOVRE, the deal may add debt without enough earnings power.
LEQEMBI adoption stays slow
High impact · Medium oddsLEQEMBI has a huge possible market, but uptake has been slowed by health system limits such as diagnosis, monitoring, and treatment setup. At-home LEQEMBI IQLIK helps with convenience, but patients still need screening and coverage. If doctors and payers move slowly, Alzheimer's revenue may not ramp fast enough.
Legacy MS decline outruns launches
High impact · High oddsBiogen's MS base is still large but fading. TECFIDERA and TYSABRI face generic and biosimilar competition. The company even paused its own new MS drug because of market crowding. VUMERITY is growing, but it may not fully offset pressure across the older MS portfolio.
SPINRAZA loses more SMA patients
Medium impact · Medium oddsSPINRAZA faces oral and gene therapy competitors in spinal muscular atrophy. The high-dose approval gives Biogen a stronger defense and may bring some patients back, but the market remains competitive. A weaker SPINRAZA base would hurt rare disease durability.
Drug pricing and policy pressure
Medium impact · Medium oddsThe IRA Medicare Part D redesign creates ongoing margin pressure, particularly for rare disease assets like SKYCLARYS. More pricing pressure, Medicare changes, or tariff shifts could weigh on sales and margins. This matters more as Biogen pushes newer high-value drugs.
In one breath
What is Biogen best known for?
Biogen is best known for neurology drugs, especially MS treatments and SPINRAZA for spinal muscular atrophy. It is now trying to become a broader company built around Alzheimer's, rare disease, immunology, and eye disease drugs.
Why did Biogen buy Apellis?
Biogen bought Apellis to add two marketed drugs right away: SYFOVRE and EMPAVELI. The deal is meant to make revenue growth less dependent on slow pipeline progress.
Why does LEQEMBI IQLIK matter?
LEQEMBI IQLIK lets patients receive Alzheimer's treatment with at-home injections instead of starting with IV infusions. That could lower the burden on patients, doctors, and infusion centers.
Is Biogen already growing again?
Yes. In Q2 2026, total core pharmaceutical revenue was $1.8 billion, up 4% year over year, and the growth products segment passed $1 billion to officially exceed the older MS portfolio.
